Prefabricated fireplace construction



March 3, 1 J. v. NORTHWOOD ETAL 3,123,063

PREFABRICATED FIREPLACE CONSTRUCTION Filed May 1, 1961 3 Sheets-Sheet 1 "III'IIIIIIIIIIIIIIIIIIIIIIdII'IIIIIII'I'IIII 3 INV EN TORS'.

JOHN v. NORTHWOOD BY JOHN w. Raw-1m ATTORNEYS March 3, 1 J. v. NORTHWOOD ETAL 3,123,063

PREFABRICATED FIREPLACE CONSTRUCTION Filed May 1, 19 61 3 Sheets-Sheet 2 s 5 28 :0 3. 66 84 ea INVEN TOR.

JOH/V v. NORTH W000 6 BY JOHN w. POSHER WNW A TTOPNE Y5 March 3, 1964 J. v. NORTHWOOD ETAL 3,123,063

PREFABRICATED FIREPLACE CONSTRUCTION Filed May 1, 1961 3 Sheets-Sheet 3 INV EN TOR.

9 3 JOHN v. IVORTHWOOD 5 BY JOHN w ROSHEF? W MW A T roe/vars United States Patent 3,123,063 PREFABRICATED FREPLACE CONSTRUCTION John V. Northwood, Lees Summit, Mo., and John W. Rushes, Box 11-46, Lake Lotawana, Lees Summit, MO.; said Northwood assignor to Sadie Miriam Northwood, Lees Summit, Mo.

Filed May 1, 1961, Ser. No. 106,603 1 Claim. (Cl. 126-120) This invention relates to a fireplace, and more particularly to a prefabricated fireplace construction adapted to be mounted in existing building structures.

This application is a continuation-in-part of our copending application for Fireplace, Serial No. 22,832, filed April 18, 1960, now Patent No. 3,049,113.

The principal objects of the present invention are to provide a light-weight prefabricated fireplace construction adapted to be mounted in a building window opening or other wall opening with ease and with minimum clearance between said fireplace construction and wooden or other flammable building members; to provide a prefabricated fireplace adapted to burn solid fuels such as logs, charcoal or the like, and formed of sheet metal; to provide a non-refractory fireplace so constructed that there is very little heat transferred from the firebox to the exterior surface of the fireplace walls; to provide a prefabricated fireplace having multiple walls so spaced and supported in relation to each other that both circulating air and fibrous insulation may be used in combination to prevent heating of exterior fireplace surfaces; to provide such a fireplace construction which is adapted to contain a revolving spit for barbecuing and grates for other methods of cooking; to provide such a construction which presents a highly decorative appearance both on the inside and outside of the building in which it is mounted; and to provide such a fireplace which is inexpensive to construct, easily stored and shipped, versatile in use, and which requires little or no care or maintenance over long periods of time.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.

P16. 1 is a perspective View of the prefabricated fireplace of this invention mounted in a building window opening and with parts broken away to reveal the inner construction thereof.

FIG. 2 is a sectional view taken through the fireplace on the line 22, FIG. 3, showing the relationships between the firebox walls and the secondary and outer walls.

PEG. 3 is a sectional view in side elevation through the fireplace showing the path of travel of air currents between the various walls.

FIG. 4 is a sectional view through the fireplace taken on the line M, FIG. 3, further showing the path of air currents between Walls.

'FIG. 5 is a perspective View of the fireplace taken from the rear thereof with parts broken away to further reveal the inner construction and relationship of parts thereof.

PEG. 6 is a detailed sectional View through the ash pan showing the configuration thereof including lips thereon for mounting same on supporting channels extending rearwardly of the fireplace.

FIG. 7 is a side elevation of the fireplace mounted in a building opening and having a portion broken away to show air flow out the chimney thereof.

FIG. 8 is a sectional view through the chimney taken on the line 8-8, FIG. 7, showing the configuration thereof.

FIG. 9 is a perspective view on an enlarged scale showing a fireplace supporting bracket.

Referring to the drawings in more detail:

The reference numeral 1 indicates generally our fireplace construction illustrated as mounted in a window opening 2 of a building wall 3. To provide for the insertion of the fireplace construction It, the window 4 has been raised and the front portion 5 of the fireplace rested upon the window sill 6. Collapsible brackets 2 are located between the fireplace construction 1 and the sill 6 to compensate for the differences in slope therebetween. The brackets 2' are adjustable in angular relation and separation by means of suitable bolts 3' extending through elongated slots 5' and threadedly engaging nuts 4. The brackets are secured to the sill 6 by means of suitable wood screws s extending therethrough, PEG. 9. The firebox 7 of the fireplace construction It extends slightly forwardly past the building wall 3 into the building and is there provided with decorative finishing membens consisting of a frame 3, a hood 9, a hearth 1t and hearth-supporting chains 11. The frame 8 also acts as front closure members for air passageways described hereinafter. Suitable sealing strips '7 are provided be tween the window runners 8 and 9' to help make the installation weatherproof. Screw hOOks lid extend through the frame 8 and into the studding ii to support the chains 11 at the upper end thereof. Fasteners 11" are fixed to the hearth 1i and secure the lower ends of the chains 11.

The firebox 7 is comprised of side walls 22 and 13, a [bottom wall 14-, a back wall 15, and a top wall 16, all constructed of sheet metal and forming a solid fuel-burning chamber opening into the building with the rear portion '17 thereof extending outwardly of the building.

The top wall 1b is spaced forwardly from the back wall 15 so as to form a draft opening 18 in the rear portion 17 of the firebox for carrying ofi fumes formed within the firebox. The fumes formed within the firebox travel upwardly through the draft opening is into a smoke chamber 19 formed within a tapered sheet metal chimney assembly 20 described more fully hereinafter. A sheet metal damper plate 21 is slidably supported on angles 22 and 23 secured to the firebox side walls 12 and 13 by suitable means such as riveting or spot welding. A knob 24 is provided on the damper plate 21 to aid in sliding same forwardly and rearwardly of the firebox 7 to control the size of the draft opening 18.

The firebox top wall 116 exhibits an upwardly extending rear portion 25 which terminates at the same height as the uppermost edges of the firebox side walls 12 and 13 and back wall 15' to form a rectangular mouth or structure 2.6 outlining the draft opening 18, as best seen in FIG. 1. The chimney assembly 2 at the lower portion 27 thereof is rectangular in structure and adapted to sleeve over the rectangular mouth 26 to provide a continuous passageway 28 for the frame traveling therethrough, FIG. 3. Clips 29 are suitably secured to the exterior surface of the back wall 15 and a transversely extending angle 36" is suitably secured adjacent the rear portion 25 of the top wall 16 to retain the chimney assembly 20 in position over the rectangular mouth 25.

The front portion 5 of the fireplace construction contains sheet metal secondary side walls 31 and 32. supported by spacers 33 outwardly spaced from and in parallel relation respectively to the firebox side walls 12. and. 13. A sheet metal secondary bottom wall '34 is supported by spacers 35 downwardly or outwardly spaced from and in parallel relation to the firebox bottom wall 14. The spacers 33 and 35 are illustrated as short portions or sections of angles secured to the respective secondary walls 3-1, 32 and 34 and having only the end portion of one leg thereof contacting the respective firebox walls 12, 13 and 14 whereby the firebox walls are substantially out of conductive contact with the secondary walls to minimize conductive heat transfer outwardly of the firebox side and bottom walls. The spaces between the firebox walls 12, i3 and 1d and the secondary walls 31, 32 and 34 form passageways 3-6, 37 and 38 respectively which freely communicate with each other to conduct a cooling air flow or current described hereinafter.

Outer sheet metal side walls 39 and 4t and an outer sheet metal bottom wall 41 are spaced outwardly of and parallel respectively to the secondary walls 31, 32. and 34. Insulation :2, such as fiberglass insulation, is contained between said secondary walls and outer walls to further limit heat transfer outwardly from the firebox side walls 12 and 13 and bottom wall 14. The hearth it} contains instnation 4 63" retained therein by means of suitable clips 41 and 42'.

The front portions 43 and 44 of the outer side walls 39 and a? are secured, for example, by spot welding to the frame 3, FIG. 2. The rear portions 45 and 46 of the outer side walls 39 and ill are turned inwardly toward and similarly secured to the firebox side walls 32 and 13 to form vertically extending strips 47 and 48 respectively, FIGS. 2 and 5. Spaced draft holes or openings 49 extend through the strips 47 and adjacent the rear edges of the secondary side walls 31 and 32 to permit communication between the atmosphere outside the building and the passageways 36 and 37. A draft opening in the form of a transversely extending slot 50 is provided adjacent the rear edge of the secondary bottom wall 34 to permit communication between the outside atmosphere and the passageway 38 adjacent the firebox bottom wall 14. Further draft openings in the form of longitudinally extending slots 51 and 52 are provided adjacent the upper edges of the secondary side walls 31 and 32 for a purpose which will become apparent hereinafter.

A sheet metal cap 53 is provided to cover the major portion of the firebox top Wall and the upper edges of the secondary side walls 31 and 32 and contact the upper portion of the outer side walls 39 and 4d at 54-.

he cap 53 exhibits a top wall 55 having insulation 53 adjacent thereto and held in place inside the cap 53 by a suitable bracket 54 The top wall 55 and insulation 53' are spaced upwardly from the firebox top wall 16 and the upper edges of the secondary side walls 31 and 32 so as to permit air to freely flow upwardly from the longitudinally extending slots 51 and 52. A transversely extending vent opening 56 is formed between the upper surface of the firebox top wall it; and 21 depending rear lip or portion 57 of the cap 53. The vent opening 56 is located substantially between the corners or intersections 58 and 59 respectively formed by the rear and upper edges of the secondary side walls 31 and 3-2. The vent opening 56 is in the form of an elongated slot which extends substantially the width of the firebox 7.

As indicated by the arrows in FIGS. 3, 4 and 5, outside air currents flow into the transversely extending slot 59 and the draft openings n? from the under side of the fireplace construction 1. The air entering into the slot 59 flows through the passageway 3S beneath the firebox bottom wall 14- and then laterally and upwardly into the passageways 36 and 37 where it is joined with the air entering the draft openings 4%. The then freely flows upwardly inot the cap 53 beneath the insulation d3 and exits through the vent opening 56. The air subsequently continues to move upwardly through a sheet metal jacket or false chimney so described hereinafter.

The false chimney fill is comprised of a box-like lower portion at having an open bottom and a chimney portion 62. The lower portion 61 is comprised of a back wall 63 having a removable access door 63, side walls 64 and 65, and a front wall 65. The access door 63 is retained against the back wall 63 by means of suitable clips 64' and 65. The front wall 66 exhibits vertically exltending lips or edges 67 and 63 adapted to engage elongated retaining clips 69 secured to the exterior of the outer side walls 39 and 4d. The retaining clips 69 receive the edges 67 and 6%; in a channel portion 66 which is open rearwardly to provide ease of insertion thereinto. The lower terminus 6'7 of the clips 69 exhibits a short forwardly facing channel 68' which prevents accidental rearward displacement of the false chimney 6% after asfireplace construction without departing from the scope of this invention. As the false chimney 6%? extends upwardly, it tapers inwardly so as to roughly follow the contour of the chimney assembly 2-1 as indicated in FIG. 5. The chimney portion 62 of the false chimney contains a true chimney 71 spaced coaxially therewithin by means of vertically extending retaining members 71 and which communicates with the upper portion of the chimney assembly 2t"; to carry olf the fumes generated within the the box 7.

A booster pipe 75 communicates with the true chimney 71 and extends downwardly within the false chimney 60 but outside the chimney assembly 26, terminating at the lower end thereof in a fan housing 76 containing a suitable conventional suction blower or fan 76' rotatably driven by an electric motor 77. An electric cable 78 is provided to carry current from a source (not shown)- through a switch 7 8 on the frame 8 to the electric motor 77. The rotation of the fan 76' sucks air through the booster pipe 75 and then exhausts same upwardly between the false chimney 60 and the firebox 7. The downdraft produced in the booster pipe 75 lowers the pressure in the chimney assembly 20, thereby increasing the draft in the firebox 7 to aid in starting fires. A damper plate 77' is pivotally supported in the booster pipe 75 to control the draft produced in the firebox 7 by the fan 76'. The damper plate '77 is positioned by a flexible cable control wire '77" terminating in a control knob 78" on the frame 8.

As best illustrated in FIGS. 2 and 3, the false chimney 6b is spaced outwardly from the firebox side walls 12 and 13 and the firebox back wall 15 providing passageways 79, 8d and 31, FIG. 2, through which outside air may freely fiow upwardly around the rear portion 17 of the firebox to cool same and then be directed upwardly through passageways 82 formed between the chimney portion 62 of the false chimney and the true chirnney 71. Both the cooling air in the passageways 79, 3t and 81 and the firebox fumes in the true chimney 71 exit from the fireplace con struction adjacent a suitable chimney cap 83 provided at the upper terminus of the chimney portion 62; Suit-- able brackets 83 and 83" secured to the building wall 3' respectively support the chimney portion 62 and the lower portion 61 of the false chimney. It is noted that an additional passageway 84 is formed between the front wall 66 of the false chimney db and the forward wall 85 of the chimney assembly 20 through which the air currents described above in connection with the passageways 36, 37 and 3% flow upwardly to be commingled with the cooling air flowing through the passageways 79, 8t and 81.

For heavy duty use, it is desirable to provide a bafile wall 84 spaced outwardly from the firebox back wall 15 but between the backwall 15 and access door 63 to V prevent heating the false chimney back wall 63 and access door 63. The baffle wall 84' is supported by means of screws 85' engaging suitable clips 85" secured to the rear of the firebox assembly.

A pair of channel members 86 and 87 extend longitudinally through the fireplace construction 1 to provide rigidity to the structure and maintain separation between the secondary bottom wall 34 and the outer bottom wall 41, FIG. 2. The channel members 86 and 87 support the rear portion of the firebox 7 by means of offset strip braces 88 secured to the respective channel members and to the side walls 12 and 13 by suitable means such as spot welding. The braces 88 support the rear portion of the firebox 7 spaced upwardly from the channel members 86 and 87 so as to permit free circulation of the air around the rear portion of the firebox 7 and to minimize the amount ofheat transferred from the firebox to the channel members. An angle 89 is secured transversely to the inside surface 90 of the false chimney back wall 63 in position to engage the rear ends 91 and 92 of the channel members 86 and 87 for upwardly supporting the rear portion of the false chimney.

An ash pan 93 adapted to contain ashes 93 is located beneath an ash opening 94 formed in the rear portion of the firebox bottom wall 14. The ash pan 93 includes lips 95 and 96 adapted to rest on upper legs 97 and 98 of the channel members 86 and 87 to removably support same spaced beneath the ash opening 94 to permit free air circulation therearound. The removal of the ash pan 93 for disposing of ashes is accomplished by tilting the pan upwardly and laterally as indicated by broken lines in FIG. 6 in order that one of the lips is freed for withdrawal downwardly and outwardly of the fireplace construction. The ash pan 93 is replaced by reversing the above steps. Suitable stops 99 are secured to the channel members 86 and 87 in spaced relation to prevent unwanted longitudinal shifting of the ash pan 93 along the channel members and to maintain the ash pan 93 spaced from the rear edge of the outer bottom wall 41 to permit air to freely enter into the transversely extending slot 50.

A strengthening channel 100 is secured to the under side and transversely of the firebox bottom wall 14 adjacent the forward portion of the ash opening 94 to add rigidity to the structure in this area. The portion of the bottom wall 14 adjacent the rear of the ash opening 94 is formed into a downwardly extending lip 101 also to add rigidity to the structure.

A vertical baflle plate 192 is positioned in the rear inside portion 17 of the firebox 7 and has vertically extending angle members 103 secured thereto and adapted to space the bafile plate 192 forwardly of and parallel to the backwall 15. The angle members 153 extend below the lower edge of the plate 1192 and rest upon the bottom wall 14 so as to support the baffie plate 102 spaced upwardly of the bottom wall 14 whereby air passing to ward the rear of the firebox may flow beneath the vertical bafile plate 192 and upwardly between same and the firebox back wall 15. A plurality of openings 104 are provided in the bottom wall 14 between the plate 162 and back wall 15 so as to provide, in addition to the air entering from the firebox and around the ash pan 93, a further source of air for commingling with the upward flow. It is noted that the air entering through the openings 194 is directed into the smoke chamber 19 rather than the passageways formed by the false chimney 69. A grate support 105 has longitudinally extending angles 106 secured to the under side thereof for maintaining said grate support spaced upwardly from the bottom wall 14 to permit air to flow thereunder toward the back wall 15. The grate support 195 is adapted to be raised and pulled slightly forwardly of the firebox 7 and tilted so as to dump ashes thereon into the ash pan 93. A stop 156' is provided on at least one angle 106 to position the support 105 in the rear of the firebox 7.

An optional warming pan 107 shown in broken lines may be positioned adjacent the hearth 16 and resting on the bottom wall 14 and on the angles 106 for supporting a coffee pot or the like (not shown). A grate 108 of any suitable conventional design for holding logs 159 up- 6 wardly of the support and forwardly of the plate 192 is shown positioned on the support 105.

Angles 110 and 111 extending longitudinally of and secured to the side walls 12 and 13 are provided to support suitable wire members or grates (not shown) for cooking foodstuffs. Also provided for cooking is a mo torized spit 112 extending transversely of the firebox 7 and driven by a motor 113 secured to the side wall 12 by means of a bracket 114. The motor 113 receives power through an electric cable 115 which may be conveniently connected with a switch 116 mounted on the frame 8 of the fireplace construction. The spit 112 includes suitable forks or tongs 117 for insertion into a roast or fowl or the like to maintain same in a fixed rotational position with respect to the spit 112 for turning same therewith in cooking over an open fire generated within the firebox 7. The spit 112 is driven through a quick disconnect socket 118 adapted to perrnit easy withdrawal thereof from the firebox 7.

The fireplace construction 1 is here illustrated as extending through a building window opening, however, it is apparent that it will also lend itself to installation totally within a building by insertion into an opening in a wall separating rooms rather than an outside wall, and providing a suitable roof opening for the chimney.

It is to be understood that while we have illustrated and described one form of our invention, it is not to be limited to the specific form or arrangement of parts herein described and shown except insofar as such limitations are included in the claim.

What we claim and desire to secure by Letters Patent is:

In combination, a building and a prefabricated fireplace construction, means providing an opening into said building, said fireplace construction being mounted on said building and extending through said opening, said fireplace construction having inwardly exposed sheet metal side walls and an inwardly exposed sheet metal bottom wall and an inwardly exposed sheet metal back wall and an inwardly exposed sheet metal top wall forming a solid fuel-burning firebox having a metallic inside surface, said firebox opening into said building and having a front portion extending into said building and a rear portion extending externally of said building, said top firebox wall being spaced from said back firebox wall and forming therewith a firebox draft opening in said rear portion of said firebox, a chimney located externally of said building, said chimney extending upwardly from and communicating with said firebox draft opening, side, bottom and top secondary walls adjacent said front portion of said firebox, spacers supporting said secondary walls in outwardly spaced relation respectively to said side, bottom and top firebox walls at said front portion of said firebox and substantially out of conductive contact therewith to minimize conductive heat transfer outwardly from said firebox front portion, front closure members extending between said secondary walls and said firebox Walls, said secondary walls and firebox walls and closure members forming freely intercommunicating firebox front portion air current passageways surrounding said firebox front portion, false chimney side walls and a false chimney rear wall respectively having lower edges and being spaced outwardly from said firebox rear portion and forming therewith firebox rear portion air current passageways, outer walls spaced outwardly of said secondary walls, means supporting said outer walls in fixed relation with respect to said secondary walls, said outer walls contacting said building for supporting said fireplace construction on said building opening providing means, said false chimney side walls and false chimney rear wall forming adjacent said lower edges thereof intake draft openings located externally of said building and spaced above the ground and directly communicating between the atmosphere outside said building and said firebox rear portion air current passageways, draft opening forming means at the rear of said side and bottom secondary walls providing communication between said front portion air current passageways and said intake draft openings, vent opening forming means at the rear of said top secondary Wall for venting air currents in said front portion air current passageways, and a false chimney front Wall, said false chimney side and rear and front Walls extending upwardly spaced from said chimney and formin exhaust passageways communicating with said rear portion passageways and said vent opening forming means, whereby cooling air enters said intake draft openings and circulates over the outer surface of said front and rear portions of said firebox and exits through said exhaust passageways.

References Cited in the file of this patent UNITED STATES PATENTS 53,880 Rogers Apr. 10, 1866 8 Winfield Apr. 6, Munroe Oct. 27, Bender May 8, Vineberg Sept. 10, Gillen May 3, Carpenter June 25, Thulrnan Feb. 4, McClellan Dec. 8, Bernstein et a1 Mar. 22, Kneass Sept. 6, Terry Nov. 29, Northwood et a1 Aug. 14,

FOREIGN PATENTS Great Britain Great Britain Great Britain Dec. 11, France May 29, 

